1. Field of the Invention
This invention is related to the field of systems and methods for preventing, deterring and detecting the unauthorized duplication of digital information, such as digital information distributed on optical media. The method relies upon a computing device executing validation code, either stored on the media itself or stored in firmware, volatile device memory provided from an external store or network transaction, or non-volatile device memory within the device, prior to allowing full access to the protected content.
2. Description of the Related Art
The electronic publishing industry, which publishes application software, computer games, appliance-console games, movies, and music on optical media is facing a growing and serious problem; namely, the piracy, unauthorized modification, and use of digital content. Since digital content itself is in essence a sequence of binary 1's and 0's, it may often be copied exactly, wherein a copy of these “bits” is identical in every way to the original, and since the tools that enable such copying are becoming more readily available, the industry is facing ever-increasing losses. Such losses may include the unauthorized duplication of a unit of optical media containing a game, a word processing program, an E-Book, a movie, or musical content.
A number of mechanisms are currently available that may be used to limit or prevent unauthorized access to digital content, including those approaches related to optical media manufacturing, modification, and protection thereof.
The most popular among these methods include methods that insert data errors into the media at the time of manufacture by producing actual bit patterns that are technically out of conformance with published standards and specifications (originally such as those set by Philips Corporation in their CD specification documents sometimes referred to as the “Red Book”, “Orange Book”, and other industry-standards-book names). In theory, the errors cannot be reproduced by copying processes or devices if those devices or processes are themselves specification conformant. However, such approaches are limited in that they do not take into account that while these bit patterns are not officially sanctioned and not specification conformant, the approach relies on unenforceable voluntary specification compliance. Even as recently as a few years ago, most device manufacturers were in fact working very hard to be specification conformant, and most copy software was also conformant, so these protective methods were effective for a period of time. However, it was realized that by making minor changes to the devices and software, they could be made to copy nearly everything, even protected titles. This resulted in sales of more devices, more copying software, and, of course, more blank media, and such devices are not in any way illegal. Certain usage is, but that is the responsibility of the purchaser. A slippery slope of sorts, but piracy is ubiquitous and part of the reason why many segments of industry and society derive financial benefit from the act of piracy. Devices have intentionally been created which ignore these specification deviations, as have software programs dedicated to copying media such as the popular “BlindRead” and “CloneCD” software products. Examples of devices that deviate from the specifications are for example CD-R and CD-RW drives manufactured under the name “Lite-On” or “Liteon”, or devices made by industry giant “Plextor”, which are engineered to copy and reproduce all bits on a disc exactly, regardless of specification conformance. Since the methods mentioned above rely on conformance to specifications and on industry consortia applying pressure to manufacturers and software companies to cause them to comply with the specifications, they are inherently flawed, because any number of such companies can, and have, carved themselves a perfectly legal market niche by breaking ranks, doing just the opposite and creating devices optimized for such unauthorized duplication usage. If copying of a medium is physically possible, then it will be copied and distributed. This is the significant challenge faced in this field; to create media authentication mechanisms that depend on detection of repeatable, measurable media properties, and which do not depend on voluntary specification compliance across a broad set of industries.
Conventional implementations of some significance include methods that depend on the existence of media errors and the detection of these errors in order to authenticate the media. These historic methods relied, as described above, upon cooperation and compliance from the makers of copying software and makers of the drives themselves. The intentionally-generated errors used by these approaches were sometimes chosen to be illegal and/or outside the appropriate specification, and the cooperating parties were encouraged to ship only those products that would ignore, or fail to fully, or correctly, copy the bit patterns. Since any and all bit patterns are inherently copyable, it was only a matter of time before one or more of these cooperating parties broke ranks and created copy software (Blind Read, Clone CD for example) and media drives (Plextor, Lite-On) that could generate an exact copy of these “uncopyable errors”, invalidating the entire class of protection technologies based on this approach. The very failing of these methods lies in that the property they detected and depended upon can be wholly, or sufficiently copied by digital means. Such prior art “Backup-Resistant” or “Copy Protected” digital media that relies upon validation code executing on a general purpose device, is able to be wholly copied if all available bits of data relied upon by the validation algorithm can be accurately duplicated at a fundamentally low enough level onto recordable media and subsequently read on legacy devices.
A class of these authentication methods are restricted to protecting optical media intended to be used in general purpose computing devices. Such media includes a wide variety of formats such as CD-ROM, CDR, CDI, CDRW, DVD-ROM, DVD-RAM, DVD+, DVDR, CD+ (also called CDPlus or Enhanced CD, or Blue Book). Other such authentication methods can protect content on Audio and Video CD's and DVD's by applying the above methods to algorithmic logic resident in firmware or non-volatile memory within the playback device, itself a computing device whose usage is much like an appliance.
Despite such developments, no current validation methods succeed at preventing accurate duplication of such protected media and the data on the media, either intended for use on general purpose computers, such as mass-produced “stamped” optical digital formats including CD-ROM, CDR, CDI, DVD-ROM, and CD+, or on appliance devices, consumer players, and game consoles.